My Time Machine hard drive recently became full, but rather than start fresh on a new drive, I wanted to move the backup history to a new drive and keep rolling from there. Before APFS, this was easy, but since the revamp of Time Machine to use APFS several years ago, there's now no official way to migrate a Time Machine backup volume to another drive.
I couldn't find anything online that might offer a home-grown solution, but through some testing, I think I've found a method that appears to successfully clone a Time Machine backup volume onto a new drive, so I wanted to share what I've learned publicly so others could use it.
MASSIVE DISCLAIMER: Though all of these steps use official Apple and Unix commands, most were not designed to be used in this way, nor did Apple intend for APFS Time Machine backup histories to be "migrated" to a different drive at all. These steps worked for me, and I've run several successful Time Machine backups on the ne